I've played multiplayer computer games using a lot of pseudonyms through the years. Here are a few of the ones I've used most:
Ediblefungus- this is a name I used in my early high school years. It comes from Homer Price, in which a town celebrates the 42 pounds of edible fungus that was the foundation of local commerce. I probably stopped using this name because it doesn't match my behavior in most games.
I Hate Art- this is a name I used playing DotA in later high school years. I don't actually hate art; I heard this phrase in a podcast and the poetry of it struck me. I liked the idea of having an independent clause as a name, but I discontinued this name because 'I Hate Art' wasn't accurate and 'I Like Art' just doesn't sound right.
Mnicholas- this is the name I've used for most of my gaming in college (so far, at least). I got the idea when reading about mnemonics in a book-- the section title was 'Mnemonics you Mneed to Mknow.' I enjoy words like gnu that start with silent consonants. I chose Mnicholas in particular because it's slightly similar to my real name, containing all the letters of 'Micah' jumbled up a bit.